tidb rule_partition_processor 源码
tidb rule_partition_processor 代码
文件路径：/planner/core/rule_partition_processor.go
// Copyright 2018 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package core
import (
"bytes"
"context"
"fmt"
gomath "math"
"sort"
"strings"
"github.com/pingcap/errors"
"github.com/pingcap/tidb/expression"
"github.com/pingcap/tidb/parser/ast"
"github.com/pingcap/tidb/parser/model"
"github.com/pingcap/tidb/parser/mysql"
"github.com/pingcap/tidb/sessionctx"
"github.com/pingcap/tidb/table"
"github.com/pingcap/tidb/table/tables"
"github.com/pingcap/tidb/types"
"github.com/pingcap/tidb/util/chunk"
"github.com/pingcap/tidb/util/collate"
"github.com/pingcap/tidb/util/mathutil"
"github.com/pingcap/tidb/util/plancodec"
"github.com/pingcap/tidb/util/ranger"
"github.com/pingcap/tidb/util/set"
"golang.org/x/exp/slices"
)
// FullRange represent used all partitions.
const FullRange = -1
// partitionProcessor rewrites the ast for table partition.
// Used by static partition prune mode.
/*
// create table t (id int) partition by range (id)
// (partition p1 values less than (10),
// partition p2 values less than (20),
// partition p3 values less than (30))
//
// select * from t is equal to
// select * from (union all
// select * from p1 where id < 10
// select * from p2 where id < 20
// select * from p3 where id < 30)
*/
// partitionProcessor is here because it's easier to prune partition after predicate push down.
type partitionProcessor struct{}
func (s *partitionProcessor) optimize(_ context.Context, lp LogicalPlan, opt *logicalOptimizeOp) (LogicalPlan, error) {
p, err := s.rewriteDataSource(lp, opt)
return p, err
}
func (s *partitionProcessor) rewriteDataSource(lp LogicalPlan, opt *logicalOptimizeOp) (LogicalPlan, error) {
// Assert there will not be sel -> sel in the ast.
switch p := lp.(type) {
case *DataSource:
return s.prune(p, opt)
case *LogicalUnionScan:
ds := p.Children()[0]
ds, err := s.prune(ds.(*DataSource), opt)
if err != nil {
return nil, err
}
if ua, ok := ds.(*LogicalPartitionUnionAll); ok {
// Adjust the UnionScan->Union->DataSource1, DataSource2 ... to
// Union->(UnionScan->DataSource1), (UnionScan->DataSource2)
children := make([]LogicalPlan, 0, len(ua.Children()))
for _, child := range ua.Children() {
us := LogicalUnionScan{
conditions: p.conditions,
handleCols: p.handleCols,
}.Init(ua.ctx, ua.blockOffset)
us.SetChildren(child)
children = append(children, us)
}
ua.SetChildren(children...)
return ua, nil
}
// Only one partition, no union all.
p.SetChildren(ds)
return p, nil
default:
children := lp.Children()
for i, child := range children {
newChild, err := s.rewriteDataSource(child, opt)
if err != nil {
return nil, err
}
children[i] = newChild
}
}
return lp, nil
}
// partitionTable is for those tables which implement partition.
type partitionTable interface {
PartitionExpr() (*tables.PartitionExpr, error)
}
func generateHashPartitionExpr(ctx sessionctx.Context, pi *model.PartitionInfo, columns []*expression.Column, names types.NameSlice) (expression.Expression, error) {
schema := expression.NewSchema(columns...)
exprs, err := expression.ParseSimpleExprsWithNames(ctx, pi.Expr, schema, names)
if err != nil {
return nil, err
}
exprs[0].HashCode(ctx.GetSessionVars().StmtCtx)
return exprs[0], nil
}
func (s *partitionProcessor) findUsedPartitions(ctx sessionctx.Context, tbl table.Table, partitionNames []model.CIStr,
conds []expression.Expression, columns []*expression.Column, names types.NameSlice) ([]int, []expression.Expression, error) {
pi := tbl.Meta().Partition
pe, err := generateHashPartitionExpr(ctx, pi, columns, names)
if err != nil {
return nil, nil, err
}
partIdx := expression.ExtractColumns(pe)
colLen := make([]int, 0, len(partIdx))
for i := 0; i < len(partIdx); i++ {
partIdx[i].Index = i
colLen = append(colLen, types.UnspecifiedLength)
}
detachedResult, err := ranger.DetachCondAndBuildRangeForPartition(ctx, conds, partIdx, colLen)
if err != nil {
return nil, nil, err
}
ranges := detachedResult.Ranges
used := make([]int, 0, len(ranges))
for _, r := range ranges {
if r.IsPointNullable(ctx) {
if !r.HighVal[0].IsNull() {
if len(r.HighVal) != len(partIdx) {
used = []int{-1}
break
}
}
highLowVals := make([]types.Datum, 0, len(r.HighVal)+len(r.LowVal))
highLowVals = append(highLowVals, r.HighVal...)
highLowVals = append(highLowVals, r.LowVal...)
pos, isNull, err := pe.EvalInt(ctx, chunk.MutRowFromDatums(highLowVals).ToRow())
if err != nil {
// If we failed to get the point position, we can just skip and ignore it.
continue
}
if isNull {
pos = 0
}
idx := mathutil.Abs(pos % int64(pi.Num))
if len(partitionNames) > 0 && !s.findByName(partitionNames, pi.Definitions[idx].Name.L) {
continue
}
used = append(used, int(idx))
} else {
// processing hash partition pruning. eg:
// create table t2 (a int, b bigint, index (a), index (b)) partition by hash(a) partitions 10;
// desc select * from t2 where t2.a between 10 and 15;
// determine whether the partition key is int
if col, ok := pe.(*expression.Column); ok && col.RetType.EvalType() == types.ETInt {
numPartitions := len(pi.Definitions)
posHigh, highIsNull, err := pe.EvalInt(ctx, chunk.MutRowFromDatums(r.HighVal).ToRow())
if err != nil {
return nil, nil, err
}
posLow, lowIsNull, err := pe.EvalInt(ctx, chunk.MutRowFromDatums(r.LowVal).ToRow())
if err != nil {
return nil, nil, err
}
// consider whether the range is closed or open
if r.LowExclude {
posLow++
}
if r.HighExclude {
posHigh--
}
var rangeScalar float64
if mysql.HasUnsignedFlag(col.RetType.GetFlag()) {
rangeScalar = float64(uint64(posHigh)) - float64(uint64(posLow)) // use float64 to avoid integer overflow
} else {
rangeScalar = float64(posHigh) - float64(posLow) // use float64 to avoid integer overflow
}
// if range is less than the number of partitions, there will be unused partitions we can prune out.
if rangeScalar < float64(numPartitions) && !highIsNull && !lowIsNull {
for i := posLow; i <= posHigh; i++ {
idx := mathutil.Abs(i % int64(pi.Num))
if len(partitionNames) > 0 && !s.findByName(partitionNames, pi.Definitions[idx].Name.L) {
continue
}
used = append(used, int(idx))
}
continue
}
// issue:#22619
if col.RetType.GetType() == mysql.TypeBit {
// maximum number of partitions is 8192
if col.RetType.GetFlen() > 0 && col.RetType.GetFlen() < int(gomath.Log2(mysql.PartitionCountLimit)) {
// all possible hash values
maxUsedPartitions := 1 << col.RetType.GetFlen()
if maxUsedPartitions < numPartitions {
for i := 0; i < maxUsedPartitions; i++ {
used = append(used, i)
}
continue
}
}
}
}
used = []int{FullRange}
break
}
}
if len(partitionNames) > 0 && len(used) == 1 && used[0] == FullRange {
or := partitionRangeOR{partitionRange{0, len(pi.Definitions)}}
return s.convertToIntSlice(or, pi, partitionNames), nil, nil
}
slices.Sort(used)
ret := used[:0]
for i := 0; i < len(used); i++ {
if i == 0 || used[i] != used[i-1] {
ret = append(ret, used[i])
}
}
return ret, detachedResult.RemainedConds, nil
}
func (s *partitionProcessor) convertToIntSlice(or partitionRangeOR, pi *model.PartitionInfo, partitionNames []model.CIStr) []int {
if len(or) == 1 && or[0].start == 0 && or[0].end == len(pi.Definitions) {
if len(partitionNames) == 0 {
return []int{FullRange}
}
}
ret := make([]int, 0, len(or))
for i := 0; i < len(or); i++ {
for pos := or[i].start; pos < or[i].end; pos++ {
if len(partitionNames) > 0 && !s.findByName(partitionNames, pi.Definitions[pos].Name.L) {
continue
}
ret = append(ret, pos)
}
}
return ret
}
func convertToRangeOr(used []int, pi *model.PartitionInfo) partitionRangeOR {
if len(used) == 1 && used[0] == -1 {
return fullRange(len(pi.Definitions))
}
ret := make(partitionRangeOR, 0, len(used))
for _, i := range used {
ret = append(ret, partitionRange{i, i + 1})
}
return ret
}
func (s *partitionProcessor) pruneHashPartition(ctx sessionctx.Context, tbl table.Table, partitionNames []model.CIStr,
conds []expression.Expression, columns []*expression.Column, names types.NameSlice) ([]int, error) {
used, _, err := s.findUsedPartitions(ctx, tbl, partitionNames, conds, columns, names)
if err != nil {
return nil, err
}
return used, nil
}
// reconstructTableColNames reconstructs FieldsNames according to ds.TblCols.
// ds.names may not match ds.TblCols since ds.names is pruned while ds.TblCols contains all original columns.
// please see https://github.com/pingcap/tidb/issues/22635 for more details.
func (s *partitionProcessor) reconstructTableColNames(ds *DataSource) ([]*types.FieldName, error) {
names := make([]*types.FieldName, 0, len(ds.TblCols))
colsInfo := ds.table.FullHiddenColsAndVisibleCols()
colsInfoMap := make(map[int64]*table.Column, len(colsInfo))
for _, c := range colsInfo {
colsInfoMap[c.ID] = c
}
for _, colExpr := range ds.TblCols {
if colExpr.ID == model.ExtraHandleID {
names = append(names, &types.FieldName{
DBName: ds.DBName,
TblName: ds.tableInfo.Name,
ColName: model.ExtraHandleName,
OrigColName: model.ExtraHandleName,
})
continue
}
if colExpr.ID == model.ExtraPidColID {
names = append(names, &types.FieldName{
DBName: ds.DBName,
TblName: ds.tableInfo.Name,
ColName: model.ExtraPartitionIdName,
OrigColName: model.ExtraPartitionIdName,
})
continue
}
if colExpr.ID == model.ExtraPhysTblID {
names = append(names, &types.FieldName{
DBName: ds.DBName,
TblName: ds.tableInfo.Name,
ColName: model.ExtraPhysTblIdName,
OrigColName: model.ExtraPhysTblIdName,
})
continue
}
if colInfo, found := colsInfoMap[colExpr.ID]; found {
names = append(names, &types.FieldName{
DBName: ds.DBName,
TblName: ds.tableInfo.Name,
ColName: colInfo.Name,
OrigTblName: ds.tableInfo.Name,
OrigColName: colInfo.Name,
})
continue
}
return nil, errors.Trace(fmt.Errorf("information of column %v is not found", colExpr.String()))
}
return names, nil
}
func (s *partitionProcessor) processHashPartition(ds *DataSource, pi *model.PartitionInfo, opt *logicalOptimizeOp) (LogicalPlan, error) {
names, err := s.reconstructTableColNames(ds)
if err != nil {
return nil, err
}
used, err := s.pruneHashPartition(ds.SCtx(), ds.table, ds.partitionNames, ds.allConds, ds.TblCols, names)
if err != nil {
return nil, err
}
if used != nil {
return s.makeUnionAllChildren(ds, pi, convertToRangeOr(used, pi), opt)
}
tableDual := LogicalTableDual{RowCount: 0}.Init(ds.SCtx(), ds.blockOffset)
tableDual.schema = ds.Schema()
appendNoPartitionChildTraceStep(ds, tableDual, opt)
return tableDual, nil
}
// listPartitionPruner uses to prune partition for list partition.
type listPartitionPruner struct {
*partitionProcessor
ctx sessionctx.Context
pi *model.PartitionInfo
partitionNames []model.CIStr
colIDToUniqueID map[int64]int64
fullRange map[int]struct{}
listPrune *tables.ForListPruning
}
func newListPartitionPruner(ctx sessionctx.Context, tbl table.Table, partitionNames []model.CIStr,
s *partitionProcessor, conds []expression.Expression, pruneList *tables.ForListPruning) *listPartitionPruner {
colIDToUniqueID := make(map[int64]int64)
for _, cond := range conds {
condCols := expression.ExtractColumns(cond)
for _, c := range condCols {
colIDToUniqueID[c.ID] = c.UniqueID
}
}
fullRange := make(map[int]struct{})
fullRange[FullRange] = struct{}{}
return &listPartitionPruner{
partitionProcessor: s,
ctx: ctx,
pi: tbl.Meta().Partition,
partitionNames: partitionNames,
colIDToUniqueID: colIDToUniqueID,
fullRange: fullRange,
listPrune: pruneList,
}
}
func (l *listPartitionPruner) locatePartition(cond expression.Expression) (tables.ListPartitionLocation, bool, error) {
switch sf := cond.(type) {
case *expression.Constant:
b, err := sf.Value.ToBool(l.ctx.GetSessionVars().StmtCtx)
if err == nil && b == 0 {
// A constant false expression.
return nil, false, nil
}
case *expression.ScalarFunction:
switch sf.FuncName.L {
case ast.LogicOr:
dnfItems := expression.FlattenDNFConditions(sf)
return l.locatePartitionByDNFCondition(dnfItems)
case ast.LogicAnd:
cnfItems := expression.FlattenCNFConditions(sf)
return l.locatePartitionByCNFCondition(cnfItems)
}
return l.locatePartitionByColumn(sf)
}
return nil, true, nil
}
func (l *listPartitionPruner) locatePartitionByCNFCondition(conds []expression.Expression) (tables.ListPartitionLocation, bool, error) {
if len(conds) == 0 {
return nil, true, nil
}
countFull := 0
helper := tables.NewListPartitionLocationHelper()
for _, cond := range conds {
cnfLoc, isFull, err := l.locatePartition(cond)
if err != nil {
return nil, false, err
}
if isFull {
countFull++
continue
}
if cnfLoc.IsEmpty() {
// No partition for intersection, just return 0 partition.
return nil, false, nil
}
if !helper.Intersect(cnfLoc) {
return nil, false, nil
}
}
if countFull == len(conds) {
return nil, true, nil
}
return helper.GetLocation(), false, nil
}
func (l *listPartitionPruner) locatePartitionByDNFCondition(conds []expression.Expression) (tables.ListPartitionLocation, bool, error) {
if len(conds) == 0 {
return nil, true, nil
}
helper := tables.NewListPartitionLocationHelper()
for _, cond := range conds {
dnfLoc, isFull, err := l.locatePartition(cond)
if err != nil || isFull {
return nil, isFull, err
}
helper.Union(dnfLoc)
}
return helper.GetLocation(), false, nil
}
// locatePartitionByColumn uses to locate partition by the one of the list columns value.
// Such as: partition by list columns(a,b) (partition p0 values in ((1,1),(2,2)), partition p1 values in ((6,6),(7,7)));
// and if the condition is `a=1`, then we can use `a=1` and the expression `(a in (1,2))` to locate partition `p0`.
func (l *listPartitionPruner) locatePartitionByColumn(cond *expression.ScalarFunction) (tables.ListPartitionLocation, bool, error) {
condCols := expression.ExtractColumns(cond)
if len(condCols) != 1 {
return nil, true, nil
}
var colPrune *tables.ForListColumnPruning
for _, cp := range l.listPrune.ColPrunes {
if cp.ExprCol.ID == condCols[0].ID {
colPrune = cp
}
}
if colPrune == nil {
return nil, true, nil
}
return l.locateColumnPartitionsByCondition(cond, colPrune)
}
func (l *listPartitionPruner) locateColumnPartitionsByCondition(cond expression.Expression, colPrune *tables.ForListColumnPruning) (tables.ListPartitionLocation, bool, error) {
ranges, err := l.detachCondAndBuildRange([]expression.Expression{cond}, colPrune.ExprCol)
if err != nil {
return nil, false, err
}
sc := l.ctx.GetSessionVars().StmtCtx
helper := tables.NewListPartitionLocationHelper()
for _, r := range ranges {
if len(r.LowVal) != 1 || len(r.HighVal) != 1 {
return nil, true, nil
}
var locations []tables.ListPartitionLocation
if r.IsPointNullable(l.ctx) {
location, err := colPrune.LocatePartition(sc, r.HighVal[0])
if types.ErrOverflow.Equal(err) {
return nil, true, nil // return full-scan if over-flow
}
if err != nil {
return nil, false, err
}
locations = []tables.ListPartitionLocation{location}
} else {
locations, err = colPrune.LocateRanges(sc, r)
if types.ErrOverflow.Equal(err) {
return nil, true, nil // return full-scan if over-flow
}
if err != nil {
return nil, false, err
}
}
for _, location := range locations {
if len(l.partitionNames) > 0 {
for _, pg := range location {
if l.findByName(l.partitionNames, l.pi.Definitions[pg.PartIdx].Name.L) {
helper.UnionPartitionGroup(pg)
}
}
} else {
helper.Union(location)
}
}
}
return helper.GetLocation(), false, nil
}
func (l *listPartitionPruner) detachCondAndBuildRange(conds []expression.Expression, exprCols ...*expression.Column) ([]*ranger.Range, error) {
cols := make([]*expression.Column, 0, len(exprCols))
colLen := make([]int, 0, len(exprCols))
for _, c := range exprCols {
c = c.Clone().(*expression.Column)
if uniqueID, ok := l.colIDToUniqueID[c.ID]; ok {
c.UniqueID = uniqueID
}
cols = append(cols, c)
colLen = append(colLen, types.UnspecifiedLength)
}
detachedResult, err := ranger.DetachCondAndBuildRangeForPartition(l.ctx, conds, cols, colLen)
if err != nil {
return nil, err
}
return detachedResult.Ranges, nil
}
func (l *listPartitionPruner) findUsedListColumnsPartitions(conds []expression.Expression) (map[int]struct{}, error) {
if len(conds) == 0 {
return l.fullRange, nil
}
location, isFull, err := l.locatePartitionByCNFCondition(conds)
if err != nil {
return nil, err
}
if isFull {
return l.fullRange, nil
}
used := make(map[int]struct{}, len(location))
for _, pg := range location {
used[pg.PartIdx] = struct{}{}
}
return used, nil
}
func (l *listPartitionPruner) findUsedListPartitions(conds []expression.Expression) (map[int]struct{}, error) {
if len(conds) == 0 {
return l.fullRange, nil
}
exprCols := l.listPrune.PruneExprCols
pruneExpr := l.listPrune.PruneExpr
ranges, err := l.detachCondAndBuildRange(conds, exprCols...)
if err != nil {
return nil, err
}
used := make(map[int]struct{}, len(ranges))
for _, r := range ranges {
if r.IsPointNullable(l.ctx) {
if len(r.HighVal) != len(exprCols) {
return l.fullRange, nil
}
value, isNull, err := pruneExpr.EvalInt(l.ctx, chunk.MutRowFromDatums(r.HighVal).ToRow())
if err != nil {
return nil, err
}
partitionIdx := l.listPrune.LocatePartition(value, isNull)
if partitionIdx == -1 {
continue
}
if len(l.partitionNames) > 0 && !l.findByName(l.partitionNames, l.pi.Definitions[partitionIdx].Name.L) {
continue
}
used[partitionIdx] = struct{}{}
} else {
return l.fullRange, nil
}
}
return used, nil
}
func (s *partitionProcessor) findUsedListPartitions(ctx sessionctx.Context, tbl table.Table, partitionNames []model.CIStr,
conds []expression.Expression) ([]int, error) {
pi := tbl.Meta().Partition
partExpr, err := tbl.(partitionTable).PartitionExpr()
if err != nil {
return nil, err
}
listPruner := newListPartitionPruner(ctx, tbl, partitionNames, s, conds, partExpr.ForListPruning)
var used map[int]struct{}
if partExpr.ForListPruning.ColPrunes == nil {
used, err = listPruner.findUsedListPartitions(conds)
} else {
used, err = listPruner.findUsedListColumnsPartitions(conds)
}
if err != nil {
return nil, err
}
if _, ok := used[FullRange]; ok {
or := partitionRangeOR{partitionRange{0, len(pi.Definitions)}}
return s.convertToIntSlice(or, pi, partitionNames), nil
}
ret := make([]int, 0, len(used))
for k := range used {
ret = append(ret, k)
}
slices.Sort(ret)
return ret, nil
}
func (s *partitionProcessor) pruneListPartition(ctx sessionctx.Context, tbl table.Table, partitionNames []model.CIStr,
conds []expression.Expression) ([]int, error) {
used, err := s.findUsedListPartitions(ctx, tbl, partitionNames, conds)
if err != nil {
return nil, err
}
return used, nil
}
func (s *partitionProcessor) prune(ds *DataSource, opt *logicalOptimizeOp) (LogicalPlan, error) {
pi := ds.tableInfo.GetPartitionInfo()
if pi == nil {
return ds, nil
}
// PushDownNot here can convert condition 'not (a != 1)' to 'a = 1'. When we build range from ds.allConds, the condition
// like 'not (a != 1)' would not be handled so we need to convert it to 'a = 1', which can be handled when building range.
// TODO: there may be a better way to push down Not once for all.
for i, cond := range ds.allConds {
ds.allConds[i] = expression.PushDownNot(ds.ctx, cond)
}
// Try to locate partition directly for hash partition.
switch pi.Type {
case model.PartitionTypeRange:
return s.processRangePartition(ds, pi, opt)
case model.PartitionTypeHash:
return s.processHashPartition(ds, pi, opt)
case model.PartitionTypeList:
return s.processListPartition(ds, pi, opt)
}
// We haven't implement partition by key and so on.
return s.makeUnionAllChildren(ds, pi, fullRange(len(pi.Definitions)), opt)
}
// findByName checks whether object name exists in list.
func (s *partitionProcessor) findByName(partitionNames []model.CIStr, partitionName string) bool {
for _, s := range partitionNames {
if s.L == partitionName {
return true
}
}
return false
}
func (*partitionProcessor) name() string {
return "partition_processor"
}
type lessThanDataInt struct {
data []int64
maxvalue bool
}
func (lt *lessThanDataInt) length() int {
return len(lt.data)
}
func compareUnsigned(v1, v2 int64) int {
switch {
case uint64(v1) > uint64(v2):
return 1
case uint64(v1) == uint64(v2):
return 0
}
return -1
}
func (lt *lessThanDataInt) compare(ith int, v int64, unsigned bool) int {
if ith == len(lt.data)-1 {
if lt.maxvalue {
return 1
}
}
if unsigned {
return compareUnsigned(lt.data[ith], v)
}
switch {
case lt.data[ith] > v:
return 1
case lt.data[ith] == v:
return 0
}
return -1
}
// partitionRange represents [start, end)
type partitionRange struct {
start int
end int
}
// partitionRangeOR represents OR(range1, range2, ...)
type partitionRangeOR []partitionRange
func fullRange(end int) partitionRangeOR {
var reduceAllocation [3]partitionRange
reduceAllocation[0] = partitionRange{0, end}
return reduceAllocation[:1]
}
func (or partitionRangeOR) intersectionRange(start, end int) partitionRangeOR {
// Let M = intersection, U = union, then
// a M (b U c) == (a M b) U (a M c)
ret := or[:0]
for _, r1 := range or {
newStart, newEnd := intersectionRange(r1.start, r1.end, start, end)
// Exclude the empty one.
if newEnd > newStart {
ret = append(ret, partitionRange{newStart, newEnd})
}
}
return ret
}
func (or partitionRangeOR) Len() int {
return len(or)
}
func (or partitionRangeOR) Less(i, j int) bool {
return or[i].start < or[j].start
}
func (or partitionRangeOR) Swap(i, j int) {
or[i], or[j] = or[j], or[i]
}
func (or partitionRangeOR) union(x partitionRangeOR) partitionRangeOR {
or = append(or, x...)
return or.simplify()
}
func (or partitionRangeOR) simplify() partitionRangeOR {
// if the length of the `or` is zero. We should return early.
if len(or) == 0 {
return or
}
// Make the ranges order by start.
sort.Sort(or)
sorted := or
// Iterate the sorted ranges, merge the adjacent two when their range overlap.
// For example, [0, 1), [2, 7), [3, 5), ... => [0, 1), [2, 7) ...
res := sorted[:1]
for _, curr := range sorted[1:] {
last := &res[len(res)-1]
if curr.start > last.end {
res = append(res, curr)
} else {
// Merge two.
if curr.end > last.end {
last.end = curr.end
}
}
}
return res
}
func (or partitionRangeOR) intersection(x partitionRangeOR) partitionRangeOR {
if or.Len() == 1 {
return x.intersectionRange(or[0].start, or[0].end)
}
if x.Len() == 1 {
return or.intersectionRange(x[0].start, x[0].end)
}
// Rename to x, y where len(x) > len(y)
var y partitionRangeOR
if or.Len() > x.Len() {
x, y = or, x
} else {
y = or
}
// (a U b) M (c U d) => (x M c) U (x M d), x = (a U b)
res := make(partitionRangeOR, 0, len(y))
for _, r := range y {
// As intersectionRange modify the raw data, we have to make a copy.
tmp := make(partitionRangeOR, len(x))
copy(tmp, x)
tmp = tmp.intersectionRange(r.start, r.end)
res = append(res, tmp...)
}
return res.simplify()
}
// intersectionRange calculate the intersection of [start, end) and [newStart, newEnd)
func intersectionRange(start, end, newStart, newEnd int) (int, int) {
var s, e int
if start > newStart {
s = start
} else {
s = newStart
}
if end < newEnd {
e = end
} else {
e = newEnd
}
return s, e
}
func (s *partitionProcessor) pruneRangePartition(ctx sessionctx.Context, pi *model.PartitionInfo, tbl table.PartitionedTable, conds []expression.Expression,
columns []*expression.Column, names types.NameSlice) (partitionRangeOR, error) {
partExpr, err := tbl.(partitionTable).PartitionExpr()
if err != nil {
return nil, err
}
// Partition by range columns.
if len(pi.Columns) > 0 {
result, err := s.pruneRangeColumnsPartition(ctx, conds, pi, partExpr, columns)
return result, err
}
// Partition by range.
col, fn, mono, err := makePartitionByFnCol(ctx, columns, names, pi.Expr)
if err != nil {
return nil, err
}
result := fullRange(len(pi.Definitions))
if col == nil {
return result, nil
}
// Extract the partition column, if the column is not null, it's possible to prune.
pruner := rangePruner{
lessThan: lessThanDataInt{
data: partExpr.ForRangePruning.LessThan,
maxvalue: partExpr.ForRangePruning.MaxValue,
},
col: col,
partFn: fn,
monotonous: mono,
}
result = partitionRangeForCNFExpr(ctx, conds, &pruner, result)
return result, nil
}
func (s *partitionProcessor) processRangePartition(ds *DataSource, pi *model.PartitionInfo, opt *logicalOptimizeOp) (LogicalPlan, error) {
used, err := s.pruneRangePartition(ds.ctx, pi, ds.table.(table.PartitionedTable), ds.allConds, ds.TblCols, ds.names)
if err != nil {
return nil, err
}
return s.makeUnionAllChildren(ds, pi, used, opt)
}
func (s *partitionProcessor) processListPartition(ds *DataSource, pi *model.PartitionInfo, opt *logicalOptimizeOp) (LogicalPlan, error) {
used, err := s.pruneListPartition(ds.SCtx(), ds.table, ds.partitionNames, ds.allConds)
if err != nil {
return nil, err
}
if used != nil {
return s.makeUnionAllChildren(ds, pi, convertToRangeOr(used, pi), opt)
}
tableDual := LogicalTableDual{RowCount: 0}.Init(ds.SCtx(), ds.blockOffset)
tableDual.schema = ds.Schema()
appendNoPartitionChildTraceStep(ds, tableDual, opt)
return tableDual, nil
}
// makePartitionByFnCol extracts the column and function information in 'partition by ... fn(col)'.
func makePartitionByFnCol(sctx sessionctx.Context, columns []*expression.Column, names types.NameSlice, partitionExpr string) (*expression.Column, *expression.ScalarFunction, monotoneMode, error) {
monotonous := monotoneModeInvalid
schema := expression.NewSchema(columns...)
tmp, err := expression.ParseSimpleExprsWithNames(sctx, partitionExpr, schema, names)
if err != nil {
return nil, nil, monotonous, err
}
partExpr := tmp[0]
var col *expression.Column
var fn *expression.ScalarFunction
switch raw := partExpr.(type) {
case *expression.ScalarFunction:
args := raw.GetArgs()
// Special handle for floor(unix_timestamp(ts)) as partition expression.
// This pattern is so common for timestamp(3) column as partition expression that it deserve an optimization.
if raw.FuncName.L == ast.Floor {
if ut, ok := args[0].(*expression.ScalarFunction); ok && ut.FuncName.L == ast.UnixTimestamp {
args1 := ut.GetArgs()
if len(args1) == 1 {
if c, ok1 := args1[0].(*expression.Column); ok1 {
return c, raw, monotoneModeNonStrict, nil
}
}
}
}
fn = raw
monotonous = getMonotoneMode(raw.FuncName.L)
// Check the partitionExpr is in the form: fn(col, ...)
// There should be only one column argument, and it should be the first parameter.
if expression.ExtractColumnSet(args...).Len() == 1 {
if col1, ok := args[0].(*expression.Column); ok {
col = col1
}
}
case *expression.Column:
col = raw
}
return col, fn, monotonous, nil
}
func minCmp(ctx sessionctx.Context, lowVal []types.Datum, columnsPruner *rangeColumnsPruner, comparer []collate.Collator, lowExclude bool, gotError *bool) func(i int) bool {
return func(i int) bool {
for j := range lowVal {
expr := columnsPruner.lessThan[i][j]
if expr == nil {
// MAXVALUE
return true
}
if con, ok := (*expr).(*expression.Constant); ok {
// Add Null as point here?
cmp, err := con.Value.Compare(ctx.GetSessionVars().StmtCtx, &lowVal[j], comparer[j])
if err != nil {
*gotError = true
}
if cmp > 0 {
return true
}
if cmp < 0 {
return false
}
} else {
// Not a constant, pruning not possible, so value is considered less than all partitions
return true
}
}
if len(lowVal) < len(columnsPruner.lessThan[i]) {
// Not all columns given
if lowExclude {
// prefix cols > const, do not include this partition
return false
}
colIdx := len(lowVal)
col := columnsPruner.partCols[colIdx]
conExpr := columnsPruner.lessThan[i][colIdx]
if conExpr == nil {
// MAXVALUE
return true
}
// Possible to optimize by getting minvalue of the column type
// and if lessThan is equal to that
// we can return false, since the partition definition is
// LESS THAN (..., colN, minValOfColM, ... ) which cannot match colN == LowVal
if !mysql.HasNotNullFlag(col.RetType.GetFlag()) {
// NULL cannot be part of the partitioning expression: VALUES LESS THAN (NULL...)
// NULL is allowed in the column and will be considered as lower than any other value
// so this partition needs to be included!
return true
}
if con, ok := (*conExpr).(*expression.Constant); ok && col != nil {
switch col.RetType.EvalType() {
case types.ETInt:
if mysql.HasUnsignedFlag(col.RetType.GetFlag()) {
if con.Value.GetUint64() == 0 {
return false
}
} else {
if con.Value.GetInt64() == types.IntergerSignedLowerBound(col.GetType().GetType()) {
return false
}
}
case types.ETDatetime:
if con.Value.GetMysqlTime().IsZero() {
return false
}
case types.ETString:
if len(con.Value.GetString()) == 0 {
return false
}
}
}
// Also if not a constant, pruning not possible, so value is considered less than all partitions
return true
}
return false
}
}
func maxCmp(ctx sessionctx.Context, hiVal []types.Datum, columnsPruner *rangeColumnsPruner, comparer []collate.Collator, hiExclude bool, gotError *bool) func(i int) bool {
return func(i int) bool {
for j := range hiVal {
expr := columnsPruner.lessThan[i][j]
if expr == nil {
// MAXVALUE
return true
}
if con, ok := (*expr).(*expression.Constant); ok {
// Add Null as point here?
cmp, err := con.Value.Compare(ctx.GetSessionVars().StmtCtx, &hiVal[j], comparer[j])
if err != nil {
*gotError = true
// error pushed, we will still use the cmp value
}
if cmp > 0 {
return true
}
if cmp < 0 {
return false
}
} else {
// Not a constant, include every partition, i.e. value is not less than any partition
return false
}
}
// if point is included, then false, due to LESS THAN
return hiExclude
}
}
func multiColumnRangeColumnsPruner(sctx sessionctx.Context, exprs []expression.Expression,
columnsPruner *rangeColumnsPruner, result partitionRangeOR) partitionRangeOR {
lens := make([]int, 0, len(columnsPruner.partCols))
for i := range columnsPruner.partCols {
lens = append(lens, columnsPruner.partCols[i].RetType.GetFlen())
}
res, err := ranger.DetachCondAndBuildRangeForIndex(sctx, exprs, columnsPruner.partCols, lens)
if err != nil {
return fullRange(len(columnsPruner.lessThan))
}
if len(res.Ranges) == 0 {
if len(res.AccessConds) == 0 && len(res.RemainedConds) == 0 {
// Impossible conditions, like: a > 2 AND a < 1
return partitionRangeOR{}
}
// Could not extract any valid range, use all partitions
return fullRange(len(columnsPruner.lessThan))
}
rangeOr := make([]partitionRange, 0, len(res.Ranges))
comparer := make([]collate.Collator, 0, len(columnsPruner.partCols))
for i := range columnsPruner.partCols {
comparer = append(comparer, collate.GetCollator(columnsPruner.partCols[i].RetType.GetCollate()))
}
gotError := false
// Create a sort.Search where the compare loops over ColumnValues
// Loop over the different ranges and extend/include all the partitions found
for idx := range res.Ranges {
minComparer := minCmp(sctx, res.Ranges[idx].LowVal, columnsPruner, comparer, res.Ranges[idx].LowExclude, &gotError)
maxComparer := maxCmp(sctx, res.Ranges[idx].HighVal, columnsPruner, comparer, res.Ranges[idx].HighExclude, &gotError)
if gotError {
// the compare function returned error, use all partitions.
return fullRange(len(columnsPruner.lessThan))
}
// Can optimize if the range start is types.KindNull/types.MinNotNull
// or range end is types.KindMaxValue
start := sort.Search(len(columnsPruner.lessThan), minComparer)
end := sort.Search(len(columnsPruner.lessThan), maxComparer)
if end < len(columnsPruner.lessThan) {
end++
}
rangeOr = append(rangeOr, partitionRange{start, end})
}
return result.intersection(rangeOr).simplify()
}
func partitionRangeForCNFExpr(sctx sessionctx.Context, exprs []expression.Expression,
pruner partitionRangePruner, result partitionRangeOR) partitionRangeOR {
// TODO: When the ranger/detacher handles varchar_col_general_ci cmp constant bin collation
// remove the check for single column RANGE COLUMNS and remove the single column implementation
if columnsPruner, ok := pruner.(*rangeColumnsPruner); ok && len(columnsPruner.partCols) > 1 {
return multiColumnRangeColumnsPruner(sctx, exprs, columnsPruner, result)
}
for i := 0; i < len(exprs); i++ {
result = partitionRangeForExpr(sctx, exprs[i], pruner, result)
}
return result
}
// partitionRangeForExpr calculate the partitions for the expression.
func partitionRangeForExpr(sctx sessionctx.Context, expr expression.Expression,
pruner partitionRangePruner, result partitionRangeOR) partitionRangeOR {
// Handle AND, OR respectively.
if op, ok := expr.(*expression.ScalarFunction); ok {
if op.FuncName.L == ast.LogicAnd {
return partitionRangeForCNFExpr(sctx, op.GetArgs(), pruner, result)
} else if op.FuncName.L == ast.LogicOr {
args := op.GetArgs()
newRange := partitionRangeForOrExpr(sctx, args[0], args[1], pruner)
return result.intersection(newRange)
} else if op.FuncName.L == ast.In {
if p, ok := pruner.(*rangePruner); ok {
newRange := partitionRangeForInExpr(sctx, op.GetArgs(), p)
return result.intersection(newRange)
} else if p, ok := pruner.(*rangeColumnsPruner); ok {
newRange := partitionRangeColumnForInExpr(sctx, op.GetArgs(), p)
return result.intersection(newRange)
}
return result
}
}
// Handle a single expression.
start, end, ok := pruner.partitionRangeForExpr(sctx, expr)
if !ok {
// Can't prune, return the whole range.
return result
}
return result.intersectionRange(start, end)
}
type partitionRangePruner interface {
partitionRangeForExpr(sessionctx.Context, expression.Expression) (start, end int, succ bool)
fullRange() partitionRangeOR
}
var _ partitionRangePruner = &rangePruner{}
// rangePruner is used by 'partition by range'.
type rangePruner struct {
lessThan lessThanDataInt
col *expression.Column
partFn *expression.ScalarFunction
// If partFn is not nil, monotonous indicates partFn is monotonous or not.
monotonous monotoneMode
}
func (p *rangePruner) partitionRangeForExpr(sctx sessionctx.Context, expr expression.Expression) (int, int, bool) {
if constExpr, ok := expr.(*expression.Constant); ok {
if b, err := constExpr.Value.ToBool(sctx.GetSessionVars().StmtCtx); err == nil && b == 0 {
// A constant false expression.
return 0, 0, true
}
}
dataForPrune, ok := p.extractDataForPrune(sctx, expr)
if !ok {
return 0, 0, false
}
unsigned := mysql.HasUnsignedFlag(p.col.RetType.GetFlag())
start, end := pruneUseBinarySearch(p.lessThan, dataForPrune, unsigned)
return start, end, true
}
func (p *rangePruner) fullRange() partitionRangeOR {
return fullRange(p.lessThan.length())
}
// partitionRangeForOrExpr calculate the partitions for or(expr1, expr2)
func partitionRangeForOrExpr(sctx sessionctx.Context, expr1, expr2 expression.Expression,
pruner partitionRangePruner) partitionRangeOR {
tmp1 := partitionRangeForExpr(sctx, expr1, pruner, pruner.fullRange())
tmp2 := partitionRangeForExpr(sctx, expr2, pruner, pruner.fullRange())
return tmp1.union(tmp2)
}
func partitionRangeColumnForInExpr(sctx sessionctx.Context, args []expression.Expression,
pruner *rangeColumnsPruner) partitionRangeOR {
col, ok := args[0].(*expression.Column)
if !ok || col.ID != pruner.partCols[0].ID {
return pruner.fullRange()
}
var result partitionRangeOR
for i := 1; i < len(args); i++ {
constExpr, ok := args[i].(*expression.Constant)
if !ok {
return pruner.fullRange()
}
switch constExpr.Value.Kind() {
case types.KindInt64, types.KindUint64, types.KindMysqlTime, types.KindString: // for safety, only support string,int and datetime now
case types.KindNull:
result = append(result, partitionRange{0, 1})
continue
default:
return pruner.fullRange()
}
// convert all elements to EQ-exprs and prune them one by one
sf, err := expression.NewFunction(sctx, ast.EQ, types.NewFieldType(types.KindInt64), []expression.Expression{col, args[i]}...)
if err != nil {
return pruner.fullRange()
}
start, end, ok := pruner.partitionRangeForExpr(sctx, sf)
if !ok {
return pruner.fullRange()
}
result = append(result, partitionRange{start, end})
}
return result.simplify()
}
func partitionRangeForInExpr(sctx sessionctx.Context, args []expression.Expression,
pruner *rangePruner) partitionRangeOR {
col, ok := args[0].(*expression.Column)
if !ok || col.ID != pruner.col.ID {
return pruner.fullRange()
}
var result partitionRangeOR
unsigned := mysql.HasUnsignedFlag(col.RetType.GetFlag())
for i := 1; i < len(args); i++ {
constExpr, ok := args[i].(*expression.Constant)
if !ok {
return pruner.fullRange()
}
switch constExpr.Value.Kind() {
case types.KindInt64, types.KindUint64:
case types.KindNull:
result = append(result, partitionRange{0, 1})
continue
default:
return pruner.fullRange()
}
var val int64
var err error
if pruner.partFn != nil {
// replace fn(col) to fn(const)
partFnConst := replaceColumnWithConst(pruner.partFn, constExpr)
val, _, err = partFnConst.EvalInt(sctx, chunk.Row{})
} else {
val, err = constExpr.Value.ToInt64(sctx.GetSessionVars().StmtCtx)
}
if err != nil {
return pruner.fullRange()
}
start, end := pruneUseBinarySearch(pruner.lessThan, dataForPrune{op: ast.EQ, c: val}, unsigned)
result = append(result, partitionRange{start, end})
}
return result.simplify()
}
type monotoneMode int
const (
monotoneModeInvalid monotoneMode = iota
monotoneModeStrict
monotoneModeNonStrict
)
// monotoneIncFuncs are those functions that are monotone increasing.
// For any x y, if x > y => f(x) > f(y), function f is strict monotone .
// For any x y, if x > y => f(x) >= f(y), function f is non-strict monotone.
var monotoneIncFuncs = map[string]monotoneMode{
ast.Year: monotoneModeNonStrict,
ast.ToDays: monotoneModeNonStrict,
ast.UnixTimestamp: monotoneModeStrict,
// Only when the function form is fn(column, const)
ast.Plus: monotoneModeStrict,
ast.Minus: monotoneModeStrict,
}
func getMonotoneMode(fnName string) monotoneMode {
mode, ok := monotoneIncFuncs[fnName]
if !ok {
return monotoneModeInvalid
}
return mode
}
// f(x) op const, op is > = <
type dataForPrune struct {
op string
c int64
}
// extractDataForPrune extracts data from the expression for pruning.
// The expression should have this form: 'f(x) op const', otherwise it can't be pruned.
func (p *rangePruner) extractDataForPrune(sctx sessionctx.Context, expr expression.Expression) (dataForPrune, bool) {
var ret dataForPrune
op, ok := expr.(*expression.ScalarFunction)
if !ok {
return ret, false
}
switch op.FuncName.L {
case ast.EQ, ast.LT, ast.GT, ast.LE, ast.GE:
ret.op = op.FuncName.L
case ast.IsNull:
// isnull(col)
if arg0, ok := op.GetArgs()[0].(*expression.Column); ok && arg0.ID == p.col.ID {
ret.op = ast.IsNull
return ret, true
}
return ret, false
default:
return ret, false
}
var col *expression.Column
var con *expression.Constant
if arg0, ok := op.GetArgs()[0].(*expression.Column); ok && arg0.ID == p.col.ID {
if arg1, ok := op.GetArgs()[1].(*expression.Constant); ok {
col, con = arg0, arg1
}
} else if arg0, ok := op.GetArgs()[1].(*expression.Column); ok && arg0.ID == p.col.ID {
if arg1, ok := op.GetArgs()[0].(*expression.Constant); ok {
ret.op = opposite(ret.op)
col, con = arg0, arg1
}
}
if col == nil || con == nil {
return ret, false
}
// Current expression is 'col op const'
var constExpr expression.Expression
if p.partFn != nil {
// If the partition function is not monotone, only EQ condition can be pruning.
if p.monotonous == monotoneModeInvalid && ret.op != ast.EQ {
return ret, false
}
// If the partition expression is fn(col), change constExpr to fn(constExpr).
constExpr = replaceColumnWithConst(p.partFn, con)
// When the partFn is not strict monotonous, we need to relax the condition < to <=, > to >=.
// For example, the following case doesn't hold:
// col < '2020-02-11 17:34:11' => to_days(col) < to_days(2020-02-11 17:34:11)
// The correct transform should be:
// col < '2020-02-11 17:34:11' => to_days(col) <= to_days(2020-02-11 17:34:11)
if p.monotonous == monotoneModeNonStrict {
ret.op = relaxOP(ret.op)
}
} else {
// If the partition expression is col, use constExpr.
constExpr = con
}
// If the partition expression is related with more than one columns such as 'a + b' or 'a * b' or something else,
// the constExpr may not a really constant when coming here.
// Suppose the partition expression is 'a + b' and we have a condition 'a = 2',
// the constExpr is '2 + b' after the replacement which we can't evaluate.
if !constExpr.ConstItem(sctx.GetSessionVars().StmtCtx) {
return ret, false
}
c, isNull, err := constExpr.EvalInt(sctx, chunk.Row{})
if err == nil && !isNull {
ret.c = c
return ret, true
}
return ret, false
}
// replaceColumnWithConst change fn(col) to fn(const)
func replaceColumnWithConst(partFn *expression.ScalarFunction, con *expression.Constant) *expression.ScalarFunction {
args := partFn.GetArgs()
// The partition function may be floor(unix_timestamp(ts)) instead of a simple fn(col).
if partFn.FuncName.L == ast.Floor {
ut := args[0].(*expression.ScalarFunction)
if ut.FuncName.L == ast.UnixTimestamp {
args = ut.GetArgs()
args[0] = con
return partFn
}
}
// No 'copy on write' for the expression here, this is a dangerous operation.
args[0] = con
return partFn
}
// opposite turns > to <, >= to <= and so on.
func opposite(op string) string {
switch op {
case ast.EQ:
return ast.EQ
case ast.LT:
return ast.GT
case ast.GT:
return ast.LT
case ast.LE:
return ast.GE
case ast.GE:
return ast.LE
}
panic("invalid input parameter" + op)
}
// relaxOP relax the op > to >= and < to <=
// Sometime we need to relax the condition, for example:
// col < const => f(col) <= const
// datetime < 2020-02-11 16:18:42 => to_days(datetime) <= to_days(2020-02-11)
// We can't say:
// datetime < 2020-02-11 16:18:42 => to_days(datetime) < to_days(2020-02-11)
func relaxOP(op string) string {
switch op {
case ast.LT:
return ast.LE
case ast.GT:
return ast.GE
}
return op
}
// pruneUseBinarySearch returns the start and end of which partitions will match.
// If no match (i.e. value > last partition) the start partition will be the number of partition, not the first partition!
func pruneUseBinarySearch(lessThan lessThanDataInt, data dataForPrune, unsigned bool) (start int, end int) {
length := lessThan.length()
switch data.op {
case ast.EQ:
// col = 66, lessThan = [4 7 11 14 17] => [5, 5)
// col = 14, lessThan = [4 7 11 14 17] => [4, 5)
// col = 10, lessThan = [4 7 11 14 17] => [2, 3)
// col = 3, lessThan = [4 7 11 14 17] => [0, 1)
pos := sort.Search(length, func(i int) bool { return lessThan.compare(i, data.c, unsigned) > 0 })
start, end = pos, pos+1
case ast.LT:
// col < 66, lessThan = [4 7 11 14 17] => [0, 5)
// col < 14, lessThan = [4 7 11 14 17] => [0, 4)
// col < 10, lessThan = [4 7 11 14 17] => [0, 3)
// col < 3, lessThan = [4 7 11 14 17] => [0, 1)
pos := sort.Search(length, func(i int) bool { return lessThan.compare(i, data.c, unsigned) >= 0 })
start, end = 0, pos+1
case ast.GE:
// col >= 66, lessThan = [4 7 11 14 17] => [5, 5)
// col >= 14, lessThan = [4 7 11 14 17] => [4, 5)
// col >= 10, lessThan = [4 7 11 14 17] => [2, 5)
// col >= 3, lessThan = [4 7 11 14 17] => [0, 5)
pos := sort.Search(length, func(i int) bool { return lessThan.compare(i, data.c, unsigned) > 0 })
start, end = pos, length
case ast.GT:
// col > 66, lessThan = [4 7 11 14 17] => [5, 5)
// col > 14, lessThan = [4 7 11 14 17] => [4, 5)
// col > 10, lessThan = [4 7 11 14 17] => [3, 5)
// col > 3, lessThan = [4 7 11 14 17] => [1, 5)
// col > 2, lessThan = [4 7 11 14 17] => [0, 5)
pos := sort.Search(length, func(i int) bool { return lessThan.compare(i, data.c+1, unsigned) > 0 })
start, end = pos, length
case ast.LE:
// col <= 66, lessThan = [4 7 11 14 17] => [0, 6)
// col <= 14, lessThan = [4 7 11 14 17] => [0, 5)
// col <= 10, lessThan = [4 7 11 14 17] => [0, 3)
// col <= 3, lessThan = [4 7 11 14 17] => [0, 1)
pos := sort.Search(length, func(i int) bool { return lessThan.compare(i, data.c, unsigned) > 0 })
start, end = 0, pos+1
case ast.IsNull:
start, end = 0, 1
default:
start, end = 0, length
}
if end > length {
end = length
}
return start, end
}
func (s *partitionProcessor) resolveAccessPaths(ds *DataSource) error {
possiblePaths, err := getPossibleAccessPaths(
ds.ctx, &tableHintInfo{indexMergeHintList: ds.indexMergeHints, indexHintList: ds.IndexHints},
ds.astIndexHints, ds.table, ds.DBName, ds.tableInfo.Name, ds.isForUpdateRead, ds.is.SchemaMetaVersion())
if err != nil {
return err
}
possiblePaths, err = filterPathByIsolationRead(ds.ctx, possiblePaths, ds.tableInfo.Name, ds.DBName)
if err != nil {
return err
}
ds.possibleAccessPaths = possiblePaths
return nil
}
func (s *partitionProcessor) resolveOptimizeHint(ds *DataSource, partitionName model.CIStr) error {
// index hint
if len(ds.IndexHints) > 0 {
newIndexHint := make([]indexHintInfo, 0, len(ds.IndexHints))
for _, idxHint := range ds.IndexHints {
if len(idxHint.partitions) == 0 {
newIndexHint = append(newIndexHint, idxHint)
} else {
for _, p := range idxHint.partitions {
if p.String() == partitionName.String() {
newIndexHint = append(newIndexHint, idxHint)
break
}
}
}
}
ds.IndexHints = newIndexHint
}
// index merge hint
if len(ds.indexMergeHints) > 0 {
newIndexMergeHint := make([]indexHintInfo, 0, len(ds.indexMergeHints))
for _, idxHint := range ds.indexMergeHints {
if len(idxHint.partitions) == 0 {
newIndexMergeHint = append(newIndexMergeHint, idxHint)
} else {
for _, p := range idxHint.partitions {
if p.String() == partitionName.String() {
newIndexMergeHint = append(newIndexMergeHint, idxHint)
break
}
}
}
}
ds.indexMergeHints = newIndexMergeHint
}
// read from storage hint
if ds.preferStoreType&preferTiKV > 0 {
if len(ds.preferPartitions[preferTiKV]) > 0 {
ds.preferStoreType ^= preferTiKV
for _, p := range ds.preferPartitions[preferTiKV] {
if p.String() == partitionName.String() {
ds.preferStoreType |= preferTiKV
}
}
}
}
if ds.preferStoreType&preferTiFlash > 0 {
if len(ds.preferPartitions[preferTiFlash]) > 0 {
ds.preferStoreType ^= preferTiFlash
for _, p := range ds.preferPartitions[preferTiFlash] {
if p.String() == partitionName.String() {
ds.preferStoreType |= preferTiFlash
}
}
}
}
if ds.preferStoreType&preferTiFlash != 0 && ds.preferStoreType&preferTiKV != 0 {
ds.ctx.GetSessionVars().StmtCtx.AppendWarning(
errors.New("hint `read_from_storage` has conflict storage type for the partition " + partitionName.L))
}
return s.resolveAccessPaths(ds)
}
func checkTableHintsApplicableForPartition(partitions []model.CIStr, partitionSet set.StringSet) []string {
var unknownPartitions []string
for _, p := range partitions {
if !partitionSet.Exist(p.L) {
unknownPartitions = append(unknownPartitions, p.L)
}
}
return unknownPartitions
}
func appendWarnForUnknownPartitions(ctx sessionctx.Context, hintName string, unknownPartitions []string) {
if len(unknownPartitions) == 0 {
return
}
warning := fmt.Errorf("unknown partitions (%s) in optimizer hint %s", strings.Join(unknownPartitions, ","), hintName)
ctx.GetSessionVars().StmtCtx.AppendWarning(warning)
}
func (s *partitionProcessor) checkHintsApplicable(ds *DataSource, partitionSet set.StringSet) {
for _, idxHint := range ds.IndexHints {
unknownPartitions := checkTableHintsApplicableForPartition(idxHint.partitions, partitionSet)
appendWarnForUnknownPartitions(ds.ctx, restore2IndexHint(idxHint.hintTypeString(), idxHint), unknownPartitions)
}
for _, idxMergeHint := range ds.indexMergeHints {
unknownPartitions := checkTableHintsApplicableForPartition(idxMergeHint.partitions, partitionSet)
appendWarnForUnknownPartitions(ds.ctx, restore2IndexHint(HintIndexMerge, idxMergeHint), unknownPartitions)
}
unknownPartitions := checkTableHintsApplicableForPartition(ds.preferPartitions[preferTiKV], partitionSet)
unknownPartitions = append(unknownPartitions,
checkTableHintsApplicableForPartition(ds.preferPartitions[preferTiFlash], partitionSet)...)
appendWarnForUnknownPartitions(ds.ctx, HintReadFromStorage, unknownPartitions)
}
func (s *partitionProcessor) makeUnionAllChildren(ds *DataSource, pi *model.PartitionInfo, or partitionRangeOR, opt *logicalOptimizeOp) (LogicalPlan, error) {
children := make([]LogicalPlan, 0, len(pi.Definitions))
partitionNameSet := make(set.StringSet)
usedDefinition := make(map[int64]model.PartitionDefinition)
for _, r := range or {
for i := r.start; i < r.end; i++ {
// This is for `table partition (p0,p1)` syntax, only union the specified partition if has specified partitions.
if len(ds.partitionNames) != 0 {
if !s.findByName(ds.partitionNames, pi.Definitions[i].Name.L) {
continue
}
}
// Not a deep copy.
newDataSource := *ds
newDataSource.baseLogicalPlan = newBaseLogicalPlan(ds.SCtx(), plancodec.TypeTableScan, &newDataSource, ds.blockOffset)
newDataSource.schema = ds.schema.Clone()
newDataSource.Columns = make([]*model.ColumnInfo, len(ds.Columns))
copy(newDataSource.Columns, ds.Columns)
newDataSource.isPartition = true
newDataSource.physicalTableID = pi.Definitions[i].ID
// There are many expression nodes in the plan tree use the original datasource
// id as FromID. So we set the id of the newDataSource with the original one to
// avoid traversing the whole plan tree to update the references.
newDataSource.id = ds.id
err := s.resolveOptimizeHint(&newDataSource, pi.Definitions[i].Name)
partitionNameSet.Insert(pi.Definitions[i].Name.L)
if err != nil {
return nil, err
}
children = append(children, &newDataSource)
usedDefinition[pi.Definitions[i].ID] = pi.Definitions[i]
}
}
s.checkHintsApplicable(ds, partitionNameSet)
if len(children) == 0 {
// No result after table pruning.
tableDual := LogicalTableDual{RowCount: 0}.Init(ds.SCtx(), ds.blockOffset)
tableDual.schema = ds.Schema()
appendMakeUnionAllChildrenTranceStep(ds, usedDefinition, tableDual, children, opt)
return tableDual, nil
}
if len(children) == 1 {
// No need for the union all.
appendMakeUnionAllChildrenTranceStep(ds, usedDefinition, children[0], children, opt)
return children[0], nil
}
unionAll := LogicalPartitionUnionAll{}.Init(ds.SCtx(), ds.blockOffset)
unionAll.SetChildren(children...)
unionAll.SetSchema(ds.schema.Clone())
appendMakeUnionAllChildrenTranceStep(ds, usedDefinition, unionAll, children, opt)
return unionAll, nil
}
func (s *partitionProcessor) pruneRangeColumnsPartition(ctx sessionctx.Context, conds []expression.Expression, pi *model.PartitionInfo, pe *tables.PartitionExpr, columns []*expression.Column) (partitionRangeOR, error) {
result := fullRange(len(pi.Definitions))
if len(pi.Columns) < 1 {
return result, nil
}
pruner, err := makeRangeColumnPruner(columns, pi, pe.ForRangeColumnsPruning, pe.ColumnOffset)
if err == nil {
result = partitionRangeForCNFExpr(ctx, conds, pruner, result)
}
return result, nil
}
var _ partitionRangePruner = &rangeColumnsPruner{}
// rangeColumnsPruner is used by 'partition by range columns'.
type rangeColumnsPruner struct {
lessThan [][]*expression.Expression
partCols []*expression.Column
}
func makeRangeColumnPruner(columns []*expression.Column, pi *model.PartitionInfo, from *tables.ForRangeColumnsPruning, offsets []int) (*rangeColumnsPruner, error) {
if len(pi.Definitions) != len(from.LessThan) {
return nil, errors.Trace(fmt.Errorf("internal error len(pi.Definitions) != len(from.LessThan) %d != %d", len(pi.Definitions), len(from.LessThan)))
}
schema := expression.NewSchema(columns...)
partCols := make([]*expression.Column, len(offsets))
for i, offset := range offsets {
partCols[i] = schema.Columns[offset]
}
lessThan := make([][]*expression.Expression, 0, len(from.LessThan))
for i := range from.LessThan {
colVals := make([]*expression.Expression, 0, len(from.LessThan[i]))
for j := range from.LessThan[i] {
if from.LessThan[i][j] != nil {
tmp := (*from.LessThan[i][j]).Clone()
colVals = append(colVals, &tmp)
} else {
colVals = append(colVals, nil)
}
}
lessThan = append(lessThan, colVals)
}
return &rangeColumnsPruner{lessThan, partCols}, nil
}
func (p *rangeColumnsPruner) fullRange() partitionRangeOR {
return fullRange(len(p.lessThan))
}
func (p *rangeColumnsPruner) getPartCol(colID int64) *expression.Column {
for i := range p.partCols {
if colID == p.partCols[i].ID {
return p.partCols[i]
}
}
return nil
}
func (p *rangeColumnsPruner) partitionRangeForExpr(sctx sessionctx.Context, expr expression.Expression) (int, int, bool) {
op, ok := expr.(*expression.ScalarFunction)
if !ok {
return 0, len(p.lessThan), false
}
switch op.FuncName.L {
case ast.EQ, ast.LT, ast.GT, ast.LE, ast.GE:
case ast.IsNull:
// isnull(col)
if arg0, ok := op.GetArgs()[0].(*expression.Column); ok && len(p.partCols) == 1 && arg0.ID == p.partCols[0].ID {
// Single column RANGE COLUMNS, NULL sorts before all other values: match first partition
return 0, 1, true
}
return 0, len(p.lessThan), false
default:
return 0, len(p.lessThan), false
}
opName := op.FuncName.L
var col *expression.Column
var con *expression.Constant
var argCol0, argCol1 *expression.Column
var argCon0, argCon1 *expression.Constant
var okCol0, okCol1, okCon0, okCon1 bool
argCol0, okCol0 = op.GetArgs()[0].(*expression.Column)
argCol1, okCol1 = op.GetArgs()[1].(*expression.Column)
argCon0, okCon0 = op.GetArgs()[0].(*expression.Constant)
argCon1, okCon1 = op.GetArgs()[1].(*expression.Constant)
if okCol0 && okCon1 {
col, con = argCol0, argCon1
} else if okCol1 && okCon0 {
col, con = argCol1, argCon0
opName = opposite(opName)
} else {
return 0, len(p.lessThan), false
}
partCol := p.getPartCol(col.ID)
if partCol == nil {
return 0, len(p.lessThan), false
}
// If different collation, we can only prune if:
// - expression is binary collation (can only be found in one partition)
// - EQ operator, consider values 'a','b','ä' where 'ä' would be in the same partition as 'a' if general_ci, but is binary after 'b'
// otherwise return all partitions / no pruning
_, exprColl := expr.CharsetAndCollation()
colColl := partCol.RetType.GetCollate()
if exprColl != colColl && (opName != ast.EQ || !collate.IsBinCollation(exprColl)) {
return 0, len(p.lessThan), true
}
start, end := p.pruneUseBinarySearch(sctx, opName, con)
return start, end, true
}
// pruneUseBinarySearch returns the start and end of which partitions will match.
// If no match (i.e. value > last partition) the start partition will be the number of partition, not the first partition!
func (p *rangeColumnsPruner) pruneUseBinarySearch(sctx sessionctx.Context, op string, data *expression.Constant) (start int, end int) {
var err error
var isNull bool
if len(p.partCols) > 1 {
// Only one constant in the input, this will never be called with
// multi-column RANGE COLUMNS :)
return 0, len(p.lessThan)
}
charSet, collation := p.partCols[0].RetType.GetCharset(), p.partCols[0].RetType.GetCollate()
compare := func(ith int, op string, v *expression.Constant) bool {
for i := range p.partCols {
if p.lessThan[ith][i] == nil { // MAXVALUE
return true
}
var expr expression.Expression
expr, err = expression.NewFunctionBase(sctx, op, types.NewFieldType(mysql.TypeLonglong), *p.lessThan[ith][i], v)
expr.SetCharsetAndCollation(charSet, collation)
var val int64
val, isNull, err = expr.EvalInt(sctx, chunk.Row{})
if val > 0 {
return true
}
}
return false
}
length := len(p.lessThan)
switch op {
case ast.EQ:
pos := sort.Search(length, func(i int) bool { return compare(i, ast.GT, data) })
start, end = pos, pos+1
case ast.LT:
pos := sort.Search(length, func(i int) bool { return compare(i, ast.GE, data) })
start, end = 0, pos+1
case ast.GE, ast.GT:
pos := sort.Search(length, func(i int) bool { return compare(i, ast.GT, data) })
start, end = pos, length
case ast.LE:
pos := sort.Search(length, func(i int) bool { return compare(i, ast.GT, data) })
start, end = 0, pos+1
default:
start, end = 0, length
}
// Something goes wrong, abort this pruning.
if err != nil || isNull {
return 0, len(p.lessThan)
}
if end > length {
end = length
}
return start, end
}
func appendMakeUnionAllChildrenTranceStep(origin *DataSource, usedMap map[int64]model.PartitionDefinition, plan LogicalPlan, children []LogicalPlan, opt *logicalOptimizeOp) {
if opt.tracer == nil {
return
}
if len(children) == 0 {
appendNoPartitionChildTraceStep(origin, plan, opt)
return
}
var action, reason func() string
used := make([]model.PartitionDefinition, 0, len(usedMap))
for _, def := range usedMap {
used = append(used, def)
}
slices.SortFunc(used, func(i, j model.PartitionDefinition) bool {
return i.ID < j.ID
})
if len(children) == 1 {
newDS := plan.(*DataSource)
newDS.id = origin.SCtx().GetSessionVars().AllocNewPlanID()
action = func() string {
return fmt.Sprintf("%v_%v becomes %s_%v", origin.TP(), origin.ID(), newDS.TP(), newDS.ID())
}
reason = func() string {
return fmt.Sprintf("%v_%v has one needed partition[%s] after pruning", origin.TP(), origin.ID(), used[0].Name)
}
} else {
action = func() string {
buffer := bytes.NewBufferString(fmt.Sprintf("%v_%v becomes %s_%v with children[",
origin.TP(), origin.ID(), plan.TP(), plan.ID()))
for i, child := range children {
if i > 0 {
buffer.WriteString(",")
}
newDS := child.(*DataSource)
newDS.id = origin.SCtx().GetSessionVars().AllocNewPlanID()
buffer.WriteString(fmt.Sprintf("%s_%v", child.TP(), newDS.ID()))
}
buffer.WriteString("]")
return buffer.String()
}
reason = func() string {
buffer := bytes.NewBufferString(fmt.Sprintf("%v_%v has multiple needed partitions[",
origin.TP(), origin.ID()))
for i, u := range used {
if i > 0 {
buffer.WriteString(",")
}
buffer.WriteString(u.Name.String())
}
buffer.WriteString("] after pruning")
return buffer.String()
}
}
opt.appendStepToCurrent(origin.ID(), origin.TP(), reason, action)
}
func appendNoPartitionChildTraceStep(ds *DataSource, dual LogicalPlan, opt *logicalOptimizeOp) {
action := func() string {
return fmt.Sprintf("%v_%v becomes %v_%v", ds.TP(), ds.ID(), dual.TP(), dual.ID())
}
reason := func() string {
return fmt.Sprintf("%v_%v doesn't have needed partition table after pruning", ds.TP(), ds.ID())
}
opt.appendStepToCurrent(dual.ID(), dual.TP(), reason, action)
}
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